Which of the following is an NEC Article 427 requirement for the installation of electrical heat tracing cables on pipelines and vessels in unclassified areas?
a. The external surfaces of any equipment that operates at temperatures above 100?F (37.77?C) must be
physically guarded, isolated, or thermally protected.
b. Branch circuits and overcurrent devices supplying the equipment must be sized at no less than 100% of the total heater load.
c. Exposed heating equipment shall bridge all expansion joints.
d. The presence of electric heating equipment must be identified using permanent caution signs or markings at the specified intervals.
d. The presence of electric heating equipment must be identified using permanent caution signs or markings at the specified intervals.
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When welding overhead, it is best to use a hard hat with a(n) _____
a. aluminum bill b. polyester cap c. rear deflector d. light color
Heat required to turn water into steam is latent heat.
Answer the following statement true (T) or false (F)
231 cubic inches = 1 gallonCubic inches / 231 = gallons7.5 gallons in one cubic footCubic feet ´ 7.5 = gallonsWater weighs 62.5 pounds per cubic foot.Cubic feet ´ 62.5 = pounds of waterWater weighs 8.33 pounds per gallon.Gallons ´ 8.33 = pounds of waterCubic centimeters / 1,000 = litersA cubic meter is 1,000 litersA liter of water weighs 1 kilogram.One kilogram = 2.2 poundsA cubic meter of water weighs 1,000 kilograms or one metric ton.Carry the answer to two decimal places. A half-sphere has a radius of 19". How many cubic feet of water will it hold?
Fill in the blank(s) with the appropriate word(s).
The subsequent problems deal with the 2-bit A/D flash converter shown below where Vmin is 0V and Vmax is 4V. Assume the comparators have standard TTL outputs (not open-collector).
If Vin is 1.5V and trigger is high, what is G1?
A. 0 B. 1